
def get_week_day_start_end_from_str(result):
    """
    解析签到时间字符串，返回周次、星期和课堂节次信息
    
    参数:
        result: str - 格式为'%Y-%m-%d %H:%M:%S的签到'的时间字符串
        
    返回:
        dict: 包含以下键的字典:
            - week: int - 周次(以2025-02-10为第1周)
            - day: int - 星期几(1-7, 周一为1)
            - start: int - 课堂节次(1-12)或None(不在任何课堂时间段)
            
    示例:
        >>> get_week_day_start_end_from_str('2025-02-17 13:30:00的签到')
        {'week': 2, 'day': 1, 'start': 6}
    """
    from datetime import datetime
    
    # 解析时间字符串
    dt = datetime.strptime(result, '%Y-%m-%d %H:%M:%S的签到')
    
    # 计算周数（以2025-02-10为第一周周一）
    base_date = datetime(2025, 2, 10)
    delta = dt - base_date
    week = delta.days // 7 + 1
    
    # 获取星期几（周一为1，周日为7）
    day = dt.isoweekday()
    
    # 判断课堂节次
    time_tuple = (dt.hour, dt.minute)
    if (7, 00) <= time_tuple < (8, 10):
        period = 1
    elif (8, 15) <= time_tuple <= (8, 55):
        period = 2
    elif (9, 10) <= time_tuple < (9, 50):
        period = 3
    elif (9, 55) <= time_tuple <= (10, 35):
        period = 4
    elif (10, 35) <= time_tuple < (11, 15):
        period = 5
    elif (13, 0) <= time_tuple < (13, 40):
        period = 6
    elif (13, 35) <= time_tuple <= (14, 25):
        period = 7
    elif (14, 35) <= time_tuple < (15, 15):
        period = 8
    elif (15, 20) <= time_tuple <= (16, 0):
        period = 9
    elif (17, 30) <= time_tuple < (18, 10):
        period = 10
    elif (18, 15) <= time_tuple <= (18, 55):
        period = 11
    elif (19, 00) <= time_tuple < (19, 40):
        period = 12
    elif (19, 40) <= time_tuple < (20, 20):
        period = 13
    else:
        period = None
    
    return {'week': week, 'day': day, 'start': period}

